In an annotation-based Spring MVC controller, what is the preferred way to set cache headers for a specific path?
In an annotation-based Spring MVC controller, what is the preferred way to set cache headers for a specific path?
The answer is quite simple:
@Controller
public class EmployeeController {
@RequestMapping(value = "/find/employer/{employerId}", method = RequestMethod.GET)
public List getEmployees(@PathVariable("employerId") Long employerId, final HttpServletResponse response) {
response.setHeader("Cache-Control", "no-cache");
return employeeService.findEmployeesForEmployer(employerId);
}
}
Code above shows exactly what you want to achive. You have to do two things. Add "final HttpServletResponse response" as your parameter. And then set header Cache-Control to no-cache.
Starting with Spring 4.2 you can do this:
import org.springframework.http.CacheControl;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import java.util.concurrent.TimeUnit;
@RestController
public class CachingController {
@RequestMapping(method = RequestMethod.GET, path = "/cachedapi")
public ResponseEntity<MyDto> getPermissions() {
MyDto body = new MyDto();
return ResponseEntity.ok()
.cacheControl(CacheControl.maxAge(20, TimeUnit.SECONDS))
.body(body);
}
}
CacheControl object is a builder with many configuration options, see JavaDoc
I found WebContentInterceptor to be the easiest way to go.
@Override
public void addInterceptors(InterceptorRegistry registry)
{
WebContentInterceptor interceptor = new WebContentInterceptor();
interceptor.addCacheMapping(CacheControl.noCache(), "/users", "admin");
registry.addInterceptor(interceptor);
}
You could extend AnnotationMethodHandlerAdapter to look for a custom cache control annotation and set the http headers accordingly.